right ascension of the mean sun
21Istanbul observatory of Taqi al-Din — The Istanbul observatory of al Din was one of the largest astronomical observatories to be built in the Islamic world. However, it only existed for several years before it was destroyed.HistoryIn 1574, Murad III became the Sultan of the Ottoman… …
22Meridian circle — Groombridge transit circle of 1806 The meridian circle, transit circle, or transit telescope is an instrument for observing the time of stars passing the meridian, at the same time measuring its angular distance from the zenith. The idea of… …
23Milky Way Galaxy — Large spiral galaxy (roughly 150,000 light years in diameter) that contains Earth s solar system. It includes the multitude of stars whose light is seen as the Milky Way, the irregular luminous band that encircles the sky defining the plane of… …
24Equinox — This article is about the astronomical event when the sun is at zenith over the Equator. For other uses, see Equinox (disambiguation). For the same event happening on other planets and setting up a celestial coordinate system, see Equinox… …
25Longitude — For Dava Sobel s book about John Harrison, see Longitude (book). For the adaptation of Sobel s book, see Longitude (TV series). Map of Earth Longitude (λ) Lines of longitude appear vertical with varying curvature in this projection, but are… …
26Vega — Starbox begin name=Vega Starbox image caption = Location of Vega in the constellation Lyra. Starbox observe epoch=J2000.0 constell=Lyra ra=RA|18|36|56.3364cite web author=Staff date=October 30, 2007 url=http://simbad.u strasbg.fr/simbad/sim… …
27Solar System — This article is about the Sun and its planetary system. For other systems, see planetary system and star system. For a list of physical and orbital statistics for the Solar System s largest bodies, see List of gravitationally rounded objects of… …
28Molniya orbit — For other uses, see Molniya (disambiguation). Figure 1: The Molniya orbit. Usually the period from perigee + 2 hours to perigee + 10 hours is used to transmit to the northern hemisphere Molniya orbit is a type of highly elliptical orbit with an… …
29List of common astronomy symbols — This is a compilation of symbols commonly used in astronomy, particularly professional astronomy.Age (stellar)* τ AgeAstrometry parametersAstrometry Parameters * Rv radial velocity * μ proper motion * π parallax * J EpochCosmological… …
30Equation of time — The equation of time is the difference over the course of a year between time as read from a sundial and time as read from a clock, measured in an ideal situation (ie. in a location at the centre of a time zone, and which does not use daylight… …
